2000
#1,496
National surname rank
Recorded bearers 21,904
First available Census row
Per 100,000 8.12
Uncommon Last name
Oleary
Anglicized form of the Irish surname Ó Laoghaire, meaning "descendant of Laoghaire," a personal name meaning "calf-herder."
According to the 2020 US Census Bureau surname tables, roughly 24,924 Americans carry the last name Oleary. That puts it at #1,607 in the national surname ranking, appearing at a frequency of 7.27 per 100,000 people (about 1 in 13,752 residents).
This page is the full Name Census profile for the Oleary surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
For British records, Name Census UK has a British surname profile for Oleary with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
25K
1 in 13,752
Census rank
#1,607
2020 decennial data
Per 100,000
7.3
Frequency rate
Recorded bearers
22K
uncommon in the US
Popularity narrative
The Census Bureau recorded 21,735 bearers of the surname Oleary in its 2020 decennial surname file. At a rate of 7.27 per 100,000 residents, it holds the 1607th position in the national surname ranking.
Among Census respondents with the surname Oleary, the largest self-reported group is White at 90.8%. The next largest groups are Hispanic (3.8%) and Two or More Races (3.1%).
Origin
Meaning and origin of Oleary
The surname O'Leary is an ancient Irish Gaelic name that originated in County Cork, Ireland. It is derived from the Irish Gaelic words 'O Laoghaire', meaning 'descendant of Laoghaire'. Laoghaire was a popular personal name in ancient Ireland, stemming from the word 'laogh' meaning 'calf' or 'wether'.
The O'Leary name has a long and distinguished history in Ireland, with many references to notable figures bearing the name in ancient texts and manuscripts. One of the earliest recorded mentions of the O'Leary name can be found in the Annals of Inisfallen, a chronicle of medieval Irish history, dating back to the 12th century.
The O'Leary clan was one of the most powerful and influential families in the medieval Kingdom of Desmond, which encompassed much of what is now County Cork and parts of neighboring counties. They held vast estates and played a significant role in the political and military affairs of the region during this period.
One of the most renowned members of the O'Leary family was Donal Cam O'Leary (1577-1660), a distinguished Irish Catholic priest and historian. He was a prominent figure during the Irish Confederate Wars of the 1640s and is best known for his work, the "Remonstrances of the Irish Catholics", which defended the rights of Irish Catholics during the turbulent period.
Another notable O'Leary was Arthur O'Leary (1729-1802), an Irish Franciscan friar and author. He is remembered for his work "An Interesting Tragi-Comic Pastoral Farce", a satirical play that lampooned the Protestant Ascendancy in Ireland.
In the realm of literature, Ellen O'Leary (1831-1889) was a celebrated Irish poet and storyteller. She is best known for her collection of folk tales and stories, which helped to preserve and promote the rich cultural heritage of Ireland.
The O'Leary name has also been carried by individuals who have made significant contributions in various fields, such as Matthew O'Leary (1913-1992), an American judge and politician who served as a member of the United States House of Representatives.
While the O'Leary name has a rich and storied history in Ireland, it has also spread to other parts of the world through emigration. Today, people bearing the O'Leary surname can be found in countries like the United States, Canada, Australia, and New Zealand, where descendants of Irish emigrants have settled and thrived.
Demographics
Ancestry and ethnicity for Oleary
Among Census respondents with the surname Oleary, the largest self-reported group is White at 90.8%. The next largest groups are Hispanic (3.8%) and Two or More Races (3.1%).
The bar chart below shows how Oleary bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Oleary surname at the time of the 2020 Census, not any inherent property of the name itself.
- White90.8% · 19,725
- Hispanic or Latino3.8% · 821
- Two or more races3.1% · 670
- Black or African American1.2% · 257
- Asian and Pacific Islander0.8% · 182
- American Indian and Alaska Native0.4% · 80
Timeline
Historical Census data for Oleary
Oleary appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#1,607
National surname rank
Recorded bearers 22,329
+425 bearers (+1.9%)
Per 100,000 7.57
Rank movement Down 111 places
2020
#1,607
National surname rank
Recorded bearers 21,735
-594 bearers (-2.7%)
Per 100,000 7.27
Rank movement No rank change
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #1,496 | 21,904 | 8.12 | First available Census row | First available Census row |
| 2010 | #1,607 | 22,329 | 7.57 | +425 bearers (+1.9%) | Down 111 places |
| 2020 | #1,607 | 21,735 | 7.27 | -594 bearers (-2.7%) | No rank change |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Oleary surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #1,607 | #1,607 | 0.0% |
| Count | 22,329 | 21,735 | -2.7% |
| Per 100K | 7.57 | 7.27 | -3.9% |
Between the 2010 and 2020 Census, the number of Oleary bearers went from 22,329 to 21,735 (-2.7% change). The surname held its position in the national ranking, remaining at #1,607.
FAQ
Oleary surname: questions and answers
How many people in the U.S. have the surname Oleary?
Name Census estimates that about 24,924 living Americans carry the surname Oleary. Using the current population baseline, that works out to roughly 1 in 13,752 residents.
How common is Oleary?
Oleary ranks #1,607 in the 2020 Census surname tables and is classified on this site as "Uncommon." The Census recorded the name at a frequency of 7.27 per 100,000 residents, which is about 7 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 21,735 people with the surname Oleary. That is different from the site's living-bearer estimate (24,924), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 7.27 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 7.27 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 7 of them to have the surname Oleary.
Has Oleary become more or less common over time?
Between 2010 and 2020, the surname Oleary went from 22,329 recorded bearers to 21,735. That is a decrease of 594 (-2.7%). In the national ranking it stayed at #1,607.
What does the Census say about the background of Oleary?
Among Census respondents with the surname Oleary, the largest self-reported group is White at 90.8%. The next largest groups are Hispanic (3.8%) and Two or More Races (3.1%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
White is the largest self-reported group for the surname Oleary in the 2020 Census, accounting for 90.8% (19,725 people in the source table).
What is the full ancestry breakdown?
Oleary appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (90.8%), Hispanic (3.8%), Two or More Races (3.1%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Oleary (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Oleary mean?
Anglicized form of the Irish surname Ó Laoghaire, meaning "descendant of Laoghaire," a personal name meaning "calf-herder." The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Oleary (7.27 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How many people have the surname Oleary?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.